学科分类
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52 个结果
  • 简介:Althoughtheterraneconceptemergedfromthestudyofnorthernhemisphereactivecontinentalmarginsandorogenicbelts,itislargelyintheSouthernHemisphere,inparticularinrelationtotheGondwanasupercontinent,whereithasseenitsfullestflowering.Newdatacontinuetoemerge,andnewmodelsandtechniquesarebeingactivelydeveloped.Forthesereasons,“TerraneProcessesatthePacific-marginofGondwana”

  • 标签: 岩层处理 冈瓦纳大陆 太平洋空隙 显生宙 地质年代
  • 简介:1.Introduction.ThelateMesozoicEastAsiancontincntalmarginwasamobilebeltsimilartorecentcontinentalares,buthadaconsidcrablcwidthmorcthan2,oookm’Thispapcrdcscribcstbegeometryofthemobilebc1t,anddiscusscsthckincmaticsanddynamics-Itwillclarifythatthermalp1umcundcrtbeEastAsiancontincntplaycdanhoportantrolei

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  • 简介:ThenorthernmarginoftheAlxablockisthejunctionofatectonicunits.Fourfirst-ordertectonicunitsaredistinguished:1.theYaganstructuralzonecharacteristicofanimmatureislandarc;2.theZhusileng-Hangwulastructuralzone,whichwasapassivecontinentalmarginintheEarlyPalaeozoicandwastransformedintoanactivecontinentalmarginintheLatePalaeozoic;3.theShalazhastructuralzonecharacteristicofamatureislandarc;4.theNuru-Langshanstructuralzone,whichwasaProterozoicorogenicbeltandlaterevolvedintoanextensionaltranstionalcrustinthePalaeozoic.Theabove-mentionedtectonicunitsdifferremarkablyinsedimentaryformations,magmaticrockassociations,metamorphismandgeochemistryandareboundedbyfaultsbetweenoneanother.

  • 标签: Alxa structural ZONE BOUNDARY ROCK association
  • 简介:MultistagesuperimposeddeformationhasbeendiscussedsystematicallybasedontheprogressofthestratigraphicsequencesofthenortheasternmarginofYangtzeBlock.Thenew-discoveredfirststagedeformationofthosesequencesoccurredfromthemiddleTriassictotheendofearlyJurassictogetherwithdevelopmentofregionalfolding,whichwasresultedfromthedeepdetachmentshearingtendingtowardNW-WNW.Thefoldsdiptoeastandfalldowntowardwest,andweresuperimposedbythemainstagefolding.Thereafter,aseriesoffoldsweredevelopedwithaxestrendingtowardnortheast.Consequentlynormalfoldsoccurredonthenormallimbswhileoverturnedfoldontheoverturnedlimbsduringthefirststagefolding.ThedetachmentorthrustwasformedfromlateJurassictoearlyCretaceous.DuetotheupliftingofDabieandtheWannanMountainsinthenorthandsouthsides,thebi-directionalthrustingbeltwasformedbygravityflowingfromtheMountainstowardthecenterofthebasinalongthenorthsideofXuanchengandsouthsideofGuichi.Thedeformationgeodynamicswasdiscussedsimplybasedonthenewlyrecognizedinformationaboutthetectonicevolution.

  • 标签: 中国 长江下游东北部板块 多级叠加变形 重力滑动 冲断层
  • 简介:Asynthesisofcrustalthicknessestimateswasmaderecentlyutilizingavailablefield,geochemical,seismicity,shearwavevelocityandgravitydatainthePhilippines.TheresultsshowthatasignificantportionofthePhilippinearchipelagoisgenerallycharacterizedbycrustwithathicknessofaround25to30kilometers.However,twozones,whicharemadeupofathickercrust(from30to65km)havealsobeendelineated.TheLuzonCentralCordilleraregionischaracterizedbythickcrust.AnotherbeltofthickenedcrustisobservedintheBicol-Negros-Panay-CentralMindanaoregion.ThispaperexaminestheinterplayoftectonicandmagmaticprocessesandtheirroleinmodifyingPhilippinearccrust.Theprocesses,whichcouldaccountfortheobservedcrustalthicknesses,arepresented.Thecontributionsofmagmaticarcsascomparedtothecontributionoftheemplacementandaccretionofophiolitecomplexestocrustalthicknessarealsodiscussed.

  • 标签: 地壳增厚 活跃边缘环境 剪力波速度 菲律宾群岛 地质构造
  • 简介:学习的水属于温暖(T=30-50°C),碱(pH=8.9-9.3),低使矿物化(TDS<235mg/l)Na-HCO3或Na这样有高度的热水SiO2(多达81mg/l)满足的4-HCO3和F(多达3.9mg/l),在东方Sikhote-Alinorogenic带的现代火山构造的恢复区域上发生。低3他集中以及N2/O2和N2/Ar比率排除深披风液体的影响。新稀土元素元素数据抑制我们水岩石相互作用发生在水来源区域的理解。水的大气的起源被从−71‰变化的稳定的同位素价值证明到−136.1‰并且从−10.8‰到−18.8‰为δ2H和δ18O分别地。REE模式反映高pH,从水岩石相互作用的resultfing和氧化条件。用Na-K和石英地温计的深含水土层温度的计算分别地显示出116.8-131.1°C和82.2-125.8°C。深差错的存在两个与反常热坡度(∼45-50K/km)定义Sikhote-Alin的热水的唯一的geochemical形状,区域,在没有现在的暴烈的活动被登记的地方。

  • 标签: 地球化学形态 化学研究 水域 俄罗斯 SIO2含量 水岩相互作用
  • 简介:<正>TheDevonianhydrotyermalsedimentationandmineralizationarewidespreadandtypicalinMaizi、KelangandChonghuerbasinsofsouthernAltaymargin,andhavetheirrespectivesignsinoccurrence,fabricandgeochemistry.Hydr)thermalsedimentaryrocksmainlyoccurintheintermittentperiodbetweenvolcanicsub(?)ycles.Theyarethin-midium-bedded,lenticularandbasicallyuniformtotheoccurrencesoftheoverlyingandunderlyingstrata.Theclassificationofthehydrothermalsedimentaryrocksisproposedbasedonthemineralcompositions.Thedetaileddescriptionsaregiventothefivetypesofhydrothermalsedimentaryrocks:silicates,feldspar-richrocks,

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  • 简介:Themarginofappreciationiscontroversialanddifficulttounderstand.SinceitsfirstreferenceinthecaseofGreecevs.UK,themeaningofthisdoctrinehasevolvedfromdeferencetoderogationfromtheEuropeanConventiontoaninflationoflanguageusedormisusedbytheStrasbourgCourttopreservetheState’s"roomformanoeuvre"or"latitudeofdeferenceorerror."Inthispaper,Idividetheconceptofmarginofappreciationintotwocategories:thesubstantiveandstructuralconcept.TheStrasbourgCourtusuallygenerouslydeferstonationaldecisionsinstructuralscrutinywhereithastorespectEuropeanpluralismandthecollectiveinterestsofthecontractingpartiesunlessdomesticdecisionsareregardedas"manifestlyunreasonable."Incontrast,theEuropeanHumanRightsCourtscrutinizescarefullyinthesubstantivesenseofmarginofappreciation.Somefactorsortestapproacheswillbeidentifiedfirst,bywhichtheCourtsubstantivelynarrowsorlimitsthescopeofmarginpreservedfortheStates.Theresultoftwoconceptualmarginsofappreciationmaybereciprocallytransformedinsomecircumstances.WhenthecollectivegoodsurelyunderminesthecoreofConventionrights,theCourtwillnotstandwiththedomesticargumentsinceitmustensuretheimplementationofpan-Europeanhumanrightsstandards.Ontheotherside,theCourthasnocapacitytofurtherincreasestrictscrutinyincaseswherethereisacomplicatedrelationshipbetweenthemeansandendsintheproportionalitytest,implyingthatdomesticcourtsarebetterplacedthanthesupranationalcourtgiventhefactthattheyknowbetterthelocalrealityandhavemorelocalknowledge.

  • 标签: MARGIN of APPRECIATION DEFERENCE PROPORTIONALITY ESSENCE
  • 简介:ThecontinentalmarginalextensionconceptdevelopedbyChinesegeologistsrecentlymaybeappliedtotheexplanationabouttheCenozoicextensionanddivergentmovementoftheEasternAsiancontinentalmargin.Fromtheviewpointofcontinentalmarginalextension,thispaperdiscussesthedeeptectonothermalmechanismofthetectonicextensionoftheEasternAsiancontinentalmargin.TheEasternAsiancontinentalmarginisanextensionalbeltwithintensivemagmatismandstructuraldeformation,geophysicallycharacterizedbycontinualearthquakesandobviousgeothermalanomaly.SeismictomographicalresultsabouttheEasternAsiancontinentalmarginimplythatthePacificPlateissubductedtowardtheEurasianPlateatalowangleandthedivingPacificPlateliesonthesurfaceofthe670-kmphasetransitionalzone.Weinterpretthisfeaturetoberesultedfromretrogressivesubductionfollowedbycontinentalmarginalextension.Ourthermalmodelingandgeodynamicalcomputationresultssuggestthattheretrogressivesubductionoccurredatabout76Maandthewithdrawalofthetrenchservedtosupplythevolumeforthecontinentalgrowth,whichledtotheformationofthegrowingfrontoftheEasternAsiancontinentalmargin.ThegrowthwidthoftheEasternAsiancontinentalmarginisabout700km.

  • 标签: 地壳热力学 亚洲东部堆积区域 地壳延伸 热力学模型
  • 简介:Inthispaper,wecalculatedmulti-scaleresidualgeoidanomalieswiththemethodofgeoidseparationprocessing,accordingtoEGM2008ultra-highordergravityfieldmodel,remove-restoretechniqueandStokesintegral.TheEastAsiancontinentalmarginwasselectedasthestudyarea.Theresidualgeoidanomalieshavebeencalculatedbyprogramming.Onthebasisofresidualgeoidanomaliesatvariousorders,theinterlayergeoidanomaliesatdifferentdepthswerecalculatedtodepictthespatialdistributioncharacteristicsoftheresidualgeoid.Finally,weconductedadetailedgeophysicalinterpretationforthestudyareaaccordingtothegeoidanomaliesincombinationwithothergeophysicaldatasets.Fourconclusionscanbeoutlinedasfollows:1)itisimpracticablethatgeoidanomaliesareusedintheinterpretationoftheshallowobjectsduetotheinfluenceoftheterrain;2)theanomaliesofresidualgeoidcanreflecttheintensityofsmall-scalemantleconvectionintheasthenosphere;3)theinterlayergeoidanomaliescanreflectthemagmaticactivitiesassociatedwiththemantleconvectionandmantleplumeindifferentscales;4)thestudyofthegeoidmayprovideanapproachfortheresearchofthesubductionzone,mantleconvectionandmantleplume.

  • 标签: EGM2008 gravity field model GEOID ANOMALIES
  • 简介:Theformationofstrathandstrathterraceiscloselyrelatedtotectonicupliftinthedrainagebasin.BasedontheinvestigationofstrathsatYandantuandChangcaogouontheeasternsegmentofthenorthernmarginfaultofAltun,andincombinationwiththepaleoclimaticdata,thetectonicupliftsincelateEpipleistoceneasrevealedbystreamterracesatthetwoplacesisdiscussed.AtYandantu,threelevelsofstreamterraces(T1,T2andT3)havedevelopedsince16kaBP,whereT1,T3andT2arefillterracesandtheburiedmajorstrathsareexposed.Theagesofthreetreadsaredatedtobeabout16.1kaBP,12.8kaBPand6.2kaBP,respectively.Thethreeterracesreflectthreetectonicupliftevents,whiletheagesofthetreadsrepresenttheoccurrencetimeoftheseevents.Thestreamisstillbevelingthebedrockandwideningthechannelatpresent,andthemodernstrathisbeinggenerated.Theupliftrateis4.8~4.5mm/asince16.1kaBPinthisarea.From12.8kaB.Pto6.2kaBP,Theupliftratewas6.4mm/a.Theupliftrateis3.1mm/asince6.2kaBP.AtChangcaogou,fourlevelsofstreamterraces(T1,T2,T3andT1′)havedevelopedsince7kaBP.Allofthemarefillterraces.Thereareburiedstrathsunderthedeposits.TheburiedmajorstrathisexposedonT3andT2andtheminorstrathonT1′andT1.Theagesoftreadsofthethreeterraces(T3,T2andT1′)are7kaBP,3kaBPand2.5kaBP,respectively.Thefourterracesreflecttwouplifteventsinducedbytectonicactivities.Oneoccurredinabout7kaBP,andtheotherin3kaBP.Theupliftrateis5.9mm/asince7.0kaBPatChangcaogou.From7kaBPto3kaBP,theupliftratewas7.0mm/a,andsince3kaBPtillnow,theupliftrateis4.7mm/a.

  • 标签: 地震构造 隆起运动 Altun 陆缘断层 宽谷阶地
  • 简介:<正>EXTENSIONOFTHECATHAYSIANDIWA-TYPEOROGENSANDCONTINENTALMARGINSPREADINGINSOUTHEASTCHINAZouHeping(DepartmentofGeology,ZhongshanUniversity,Guangzhou,510275,China)lateorogenicextension,Diwa,crustobody,continental-margin-spreading,SoutheastChina.Adynamicmechanism,"lowerlithosphericdelaminationandextensionoftheCathaysianDiwa-typeorogens",hasbeenputforwardtoexplaintheformationoftheCenozoiccontinental-margin-spreading-beltinSoutheastChina.Theprocessesofformationanddevelop-mentforthebeltarefromthestageoftheCathaysianDiwa-typeorogensatwhichcompressionandthickeningofcurstobodiesprevailed,tothestageofthebasin-and-range-typestructuresatwhichthelateorogeniccrustalextensionoccurred,andthentothestageoftheepicontinentalDiwa-typeriftsatwhichthelithosphericextensiontookplace.

  • 标签: late OROGENIC EXTENSION DIWA crustobody continental-margin-spreading
  • 简介:Eolian灰尘免职是亲密地与大气的循环和来源区域的环境背景有关,并且因此是为学习大气的发行量模式和paleoclimatic变化的进化历史的一个无价的工具。识别任何eolian存款的起源为重建是关键的不仅灰尘来源区域的paleoenvironmental历史,而且为理解各种各样的索引的paleoclimatic意义。从西藏的高原(TP)的东方边缘上的Garze区域的黄土和paleosol样品被分析为他们的元素(专业和踪迹元素)并且同位素(Sm-Nd)地球化学并且与那些相比,北汉语(NC),黄土在一样的年龄形成了。结果证明Garze黄土和paleosol样品的geochemical作文类似于中国黄土高原(CLP)上的那些eolian存款,并且也类似于平均UCC。这显示TP的东方边缘上的eolian存款从经历了众多的上面的外壳的再循环过程的混合得好的沉积protoliths被导出,就就象CLP黄土存款。与NC黄土相比,然而,Garze样品有更高的ΣREE,李,Rb,Zr,C,Hf和双性人集中,更高的TiO2/Al2O3,Hf/Nb,La/Nb,Th/Nb和更低的K2O/TiO2,Zr/Hf,Ba/Rb比率。从Sm-Nd同位素的地球化学,εNd(0)和147Sm/144Garze黄土和paleosol样品的Nd价值清楚地比NC黄土低。,更高级的双性人,Zr和Hf集中与在这个区域的广泛地分布式的acid-magmatic岩石相关李,的更高的内容C,Rb被归因于TP的高背景价值。Garze黄土和paleosol的geochemical特征进一步取样证明冰川的本地人和另外的第四级的由岩屑形成的沉积是主要为TP的东方边缘上的eolian存款的贡献者。在在不同时间形成的Garze黄土和paleosol样品的稳定的元素集中和他们的比率与NC黄土比较有相对更大的变化范围,显示自从晚早的更新世,为eolian存款的来源区域是不稳定的。我们与TP的uplift

  • 标签: 青藏高原东缘 地球化学特征 风尘堆积 中国黄土高原 同位素地球化学 土壤样品
  • 简介:TheeasternmarginofTibetanPlateauisoneofthemostactivezonesoftectonicdeformationandseismicityinChina.Tomonitorstrainbuildupandbenefitseismicriskassessment,weconstructed14survey-modeglobalpositionsystem(GPS)stationsthroughoutthenorthwestofLongmenshanfault.AnewGPSfieldover1999–2011isderivedfrommeasurementsofthenewlybuiltandpre-existingstationsinthisregion.Sequentially,twostrainratefields,oneprecedingandtheotherfollowingthe2008MW7.9Wenchuanearthquake,areobtainedusingtheGausianweightingapproach.Strainfieldover1999–2007showsdistinctstrainpartitioningpriortothe2008MW7.9Wenchuanearthquake,withcompressionspreadingoveraroundLongmenshanarea.Strainfieldderivedfromthetwomeasurementsin2009and2011showsthattheareaaroundLongmenshancontinuestobeunderstrikingcompression,asthepatternprecedingtheWenchuanearthquake,implyingacausativefactorofthesequentof2013MW6.7Lushanearthquake.OurGPSderiveddilatationshowsthatboththeWenchuanandLushanearthquakesoccurredwithinthedomainofpronouncedcontraction.TheGPSvelocitiesdemonstratethattheLongribafaultunderwentslightmotionwiththefaultnormaland-parallelratesat1.0±2.5mmand0.3±2.2mm/a;theLongmenshanfaultdisplayedslowactivity,withafault-normalrateat0.8±2.5mm/a,andafault-parallelrateat1.8±1.7mm/a.LongribafaultisonaparwithLongmenshanfaultinstrainpartitioningtoaccommodatethesoutheastwardmotionofeasternmarginoftheTibetanPlateau.Integratedanalysisofprincipalstraintensors,meanprincipalstress,andfastdirectionsofmantleanisotropyshowsthatwestofSichuanischaracterizedasmechanicallystrongcrust-mantlecoupling.更多还原

  • 标签: 青藏高原东缘 应变机制 构造意义 龙门山断裂带 地震活动 多相